Singularity-based mechanism with high responsiveness

We propose a singularity-based mechanism (SBM) to exploit the singular configuration that improves the angular acceleration instead of constraining the movement. The tradeoff between the responsiveness and the range of motion is achieved by varying a length of linkage in the SBM. In this paper, we clarify the responsiveness of the SBM using the dynamics analysis. For the demonstration, we build an experimental SBM system with the high responsiveness, a practical range of motion, and a size comparable to a human arm. In the experiment, the effectiveness of the SBM is shown in a vertical lifting task. The characteristic of the SBM that generates a large acceleration at start is similar to the human arm moved by a muscle. The similarity between the SBM and the human arm is analyzed in terms of the static torque.